The intermediate zone started to possess ALDH1L1+ cells at 19 GW, and only single cells or separate fibers of weak ALDH1L1-immunoreactivity could be seen earlier in the period at 15–18 GW. Neocortical cortical plate and subplate stably possessed ALDH1L1-immunoreactive cells at 19–20 GW (Kharlamova et al., 2024).
At 19 GW and later, ventricular zone and inner part of subventricular zone demonstrated GFAP immunoreactivity with minor regional differences: abundant immunoreactivity was demonstrated in ventral part of the medial ventricular zone near the corpus callosum area, the entire ventricular zone and inner subventricular zone (of both medial and lateral walls) showed less immunoreactive cells. Separate GFAP-immunoreactive fibers and cells appeared at the 19 GW within intermediate zone, minor wavy fibers appeared in the subplate and separate fibers and cells appeared in the outer subventricular zone part bordering with intermediate zone (Kharlamova et al., 2024).
NeuN-immunoreactive cells in the calcarine sulcus were concentrated mainly in layer VI, whereas in the upper layers, such cells were almost entirely absent. In the area of the smoothed parietooccipital sulcus, the distribution of NeuN-immunoreactive cells was more uniform (Godovalova et al., 2024).
S100
Ventricular zone and inner subventricular zone remained immunonegative till the end of the early fetal period: at 19 GW, separate cells with S100-immunoreactive nuclear/soma were registered in the inner part of subventricular zone, S-100 + cells were more abundant within the most ventral part of medial inner subventricular zone, the neuroepithelial cells of ventricular zone remained mainly immunonegative by contrast with the anti-ALDH1L1- and anti-GFAP cases (Kharlamova et al., 2024).
Sox9
The pattern of the Sox9-immunoreactive cell distribution (for more information see Kharlamova et al., 2024).
